Within the first 4 hours, I’d escalate from email to live touchpoints: a short Slack message to the team lead and PM, followed by a 15–20 minute video or in-person huddle. I’d come with a simple Kanban-style view (in Jira/Trello/Asana) highlighting slipped items, dependencies, and the impact (e.g., go-live at risk by 5 days, affecting 3 downstream teams). In that meeting, I’d clarify blockers, renegotiate realistic micro-deadlines for the next 48–72 hours, and agree on owners. I’d then publish a one-page updated plan with daily check-ins (10–15 minutes) and visible status in our project dashboard (e.g., Smartsheet/Notion). If risks remain high after 24 hours, I’d involve the initiative sponsor to re-prioritize scope or resources so we protect the overall milestone.